Burner with tangential gas inlet

ABSTRACT

A gas burner for producing an annular array of flames includes a circular gas distribution channel distributing gas from an inlet to a circular array of burning ports. The burner includes a gas injector delivering gas to the gas distribution channel tangentially. This reduces the overall footprint of the burner to facilitate its incorporation in small appliances.

[0001] This application is related to co-owned U.S. Ser. No. 10/___,___(Docket #MAC-007) filed on even date herewith and entitled “PatioHeater”.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to burners with a tangential gas.More particularly, although not exclusively, the invention relates to acircular or toroidal burner for use in a heating appliance, such as, butnot limited to patio heaters.

[0004] 2. State of the Art

[0005] Patio heaters, often used at outdoor restaurants, include a postat the top of which there is situated a gas-burning radiator. Theseradiate heat primarily downwardly toward restaurant patrons seated atthe restaurant's tables alongside which the heaters are situated. Thislocalised radiation source can be uncomfortable for the restaurant'spatrons, particularly over a period of time.

[0006] Known circular gas burners as used in water heaters and cook-topsfor example have a radially extending gas inlet. This not only increasesthe “footprint” of the burner itself, but also hinder the flow of gasinto the annular space beneath the burning ports. Also, where the inletextends radially from the burner, the gas line attached theretoeffectively further increases the required space as the gas line must bebent or curved back (or otherwise contorted to thereby wasted space) forconnection to a gas-flow control device that might be mounted on theexterior of the appliance. Furthermore, the gas must turn sharply afterhaving been injected into the annular space via the inlet.

[0007] The burner should preferably be space-efficient in itsconstruction, and have a small footprint so as to enable reduction inthe size of the appliance in which it is incorporated. The arrangementof the gas inlet should be such that a gas supply line can be connectedthereto in a space-efficient manner.

[0008] A burner should also provide efficient gas distribution to itsburning ports.

SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to provide aspace-efficient gas burner for use in a heating appliance.

[0010] It is another object of the present invention to provide a gasburner giving efficient gas distribution to its burning ports.

[0011] It is a further object of the present invention to provide acircular gas burner having a tangential gas inlet to reduce the“footprint” of the burner and reduce space requirements within theappliance for any gas supply line.

[0012] It is an additional object of the invention to provide alow-mounted gas burner which can provide even heat radiation to heat theinside of a tubular heat exchanger; e.g., a post of a patio heater.

[0013] There is disclosed herein a gas burner having a substantiallycircular gas distribution channel distributing gas from an inlet thatincludes a gas injector delivering gas to the gas distribution channeltangentially.

[0014] Preferably, the gas distribution channel distributes the gas to asubstantially circular array of burning ports.

[0015] Preferably the inlet includes a mixing tube through which gasfrom the injector passes tangentially to the distribution channel.

[0016] Preferably a venturi is situated in the mixing tube so as toaccelerate gas injected by the injector into the distribution channel.

[0017] The burning ports can be circular apertures.

[0018] Alternatively, the burning ports can be radially extending slots.

[0019] Preferably the distribution channel is annular so as to allowsecondary combustion air to pass through a centre thereof.

[0020] There is further disclosed herein a heating appliance having theabove-disclosed gas burner mounted therein so as to

[0021] Preferably, the appliance further includes a gas supply lineextending substantially co-linearly with and from the gas inlet directlyto a gas-flow control valve.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Preferred forms of the present invention will now be described byway of example with reference to the accompanying drawings, wherein:

[0023]FIG. 1 is a schematic plan view of a gas burner,

[0024]FIG. 2 is a schematic cross-sectional elevation of a gasdistribution channel,

[0025]FIG. 3 is a schematic side elevation of the gas burner of FIG. 1,

[0026]FIG. 4 is another schematic side elevation of the gas burner ofFIG. 1,

[0027]FIG. 5 is a schematic plan view of an alternative gas burner,

[0028]FIG. 6 is a schematic side elevation of the burner of FIG. 5,

[0029]FIG. 7 is another schematic side elevation of the gas burner ofFIG. 5, and

[0030]FIG. 8 is a schematic cross-sectional elevational view of a patioheater having the gas burner of either FIG. 1 of FIG. 5 therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] In FIGS. 1 to 4 of the accompanying drawings there isschematically depicted a circular or toroidal burner 10. The burner 10might typically be formed as a steel pressing, but might alternativelybe cast or otherwise fabricated. The burner 10 includes a circular gasdistribution channel 21. Channel 21 is of annular or toroidal form.

[0032] The burner 10 includes a mixing tube 14 via which gas entersventuri or constriction 13 via which gas is accelerated after havingbeen injected by an injector 12.

[0033] Gas is delivered to the injector 12 via an inlet 11. Agas-delivery line extending say from a control valve would be attachedto the inlet 11. The gas delivery line might extend straight from theinlet 11 to the control valve as a continuous straight tangent. As onecould imagine, this would significantly reduce the footprint of theappliance within which the burner is incorporated, as compared to thesituation where the mixing tube extends radially from an edge of theburner 10.

[0034] The burner 10 includes a plurality of burning ports 15 facingupwardly in use. Optionally, the burner ports may also be located on thesides of the distribution channel. These are distributed the whole wayaround the burner to provide a circular array of flames. As shown inFIG. 1, the mixing tube 14 extends substantially tangentially from thecircular array of burning ports 15. However, it could be said that themixing tube 14 is offset slightly radially from a true tangentialposition. In an alternative construction, the mixing tube 40 could beformed as just beneath the other end portion of the distributionchannel. This remote or other end portion would be blocked. In such aconstruction, the mixing tube 14 would extend linearly from the inletend of the mixing channel beneath the overlapping end portion.

[0035] As shown in FIG. 2, the distribution channel might be ofhexagonal cross-section. However, the cross-section might be circular,square, rectangular or any other conveniently manufactured shape.

[0036] FIGS. 5 to 7 depict an alternative burner 20, also ofcircular/toroidal form and including features similar to those describedwith reference to FIGS. 1 to 4. In this embodiment however, the burningports 15 are in the form of radially extending slots. However, there aremany styles of burner porting possible. For example, there might be oneor more continuous circular slots extending circumferentially.

[0037] In both of the embodiments of FIGS. 1 to 4 and FIGS. 5 to 7,primary air 16 is drawn the into the venturi 17 via suction forcesinduced as a result of gas injection by the injector 12. Also, in eachembodiment, secondary combustion through the large hole H shown in theplan view of FIGS. 1 and 5) and the area radially outside of the burner.

[0038]FIG. 8 depicts a typical installation of a burner 10 or 20. Thisdiagram shows a patio heater having a heat exchanger 17 within whichthere is situated an exhaust gas scrub enhancer 19. The heat exchangeris in the form of a circular cross-sectioned, vertically oriented pipe.It might be desired to direct a ring of flame against the inner surfaceof the heat exchanger, without wasting flame up through the centre ofthe heat exchanger. The patio heater of FIG. 8 also includes a heatreflector 30 as described in more detail in U.S. Ser. No. 10/___,___(Docket #MAC-007) previously incorporated by reference herein.

[0039] The gas burner's described above are particularly suited to suchan application, because a patio heater should not take up too much floorspace, particularly in a small outdoor restaurant. The compact heatexchanger of small footprint (with reduced space requirements for thegas-delivery pipe) resulting from the tangential arrangement of the gasinlet and venturi is eminently suitable to such an application.

[0040] It should be appreciated that modifications and alterationsobvious to those skilled in the art are not to be considered as beyondthe scope of the present invention. For example, instead of beingcircular, the burner might be oval shaped.

[0041] Also, in a gas cook-top arrangement for example, the burner mightbe complemented by a centrally-mounted burner enabling a broad spread offlame-control and this might be particularly suited to cooking with awok.

1. A gas burner having a substantially circular gas distribution channeldistributing gas from an inlet that includes a gas injector deliveringgas to the gas distribution channel tangentially.
 2. The gas burner ofclaim 1, wherein the gas distribution channel includes a substantiallycircular array of burning ports.
 3. The gas burner of claim 1, whereinthe inlet includes a mixing tube through which gas from the injectorpasses tangentially to the distribution channel.
 4. The gas burner ofclaim 3 further including a venturi situated in the mixing tube andarranged to accelerate gas injected by the injector into thedistribution channel.
 5. The gas burner of claim 2, wherein the burningports are circular apertures.
 6. The gas burner of claim 2, wherein theburning ports are radially extending slots.
 7. The gas burner of claim1, wherein the distribution channel is annular so as to allow secondarycombustion air to pass through a centre thereof.
 8. A heating appliancehaving the gas burner of claim 1 mounted therein so as to direct heat toa heat exchanger.
 9. The heating appliance of claim 8 further includinga gas supply line extending substantially co-linearly with and from thegas inlet directly to a gas-flow control valve.